ALBANY – Gov. Spitzer’s office is threatening to file a state Ethics Commission complaint against former Gov. Pataki unless Pataki pays the full price of yet another costly, last-minute charter flight taken before he left office, The Post has learned.

Spitzer’s office, in a letter to one of the former governor’s top aides Thursday, put Pataki on notice that it would not pay the full $16,000-plus cost of the December flight – an upstate “economic development” swing that included the lame-duck governor and Buffalo-area U.S. Rep. Tom Reynolds (R).

The action came after Spitzer’s aides concluded that Pataki’s office illegally “split” the bill in order to circumvent the state Finance Law’s requirement that contracts over $15,000 be publicly advertised for bid, a Spitzer administration official told The Post.

That view was shared by state Comptroller Tom DiNapoli, who has refused to pay the charter company’s bill.

“It was really outrageous,” the Spitzer administration official said.

Aides to Pataki initially agreed to have the ex-governor’s political-action committee pay $3,500 for the “political portion” of the trip – angering some Spitzer aides because of the concession that politics was a factor in the swing.

But when Pataki refused to pay the full cost, Spitzer aides threatened disciplinary action by the Ethics Commission, which could fine or censure the ex-governor.

Late yesterday, a day after learning about The Post’s pending story, Pataki spokesman David Catalfamo said the cost of the flight “is in the process of being paid.”

The Post disclosed earlier this year that the Comptroller’s Office had blocked payment of a $10,712 bill for a December charter flight taken by Pataki and his aides to Virginia.

Pataki’s PAC eventually paid for that flight.

*

Mayor Bloomberg will be answering questions again today about a possible run for governor in 2010 from his biggest booster for the job, Senate Majority Leader Joseph Bruno.

Bloomberg is slated to meet behind closed doors with members of the Senate’s Republican majority, in part to push – via a PowerPoint presentation – his controversial “congestion pricing” plan to reduce Manhattan traffic.

While Bloomberg insists he’s not interested in running for the state’s top spot, Bruno predicts the mayor will become the GOP standard-bearer against Spitzer after term limits force Hizzoner to leave office in 2009.